I have undergone 4 sessions of chemo with Carboplatin and Pemetrexed and my bone metastasis and lung lesions are all greatly reduced again and I have been put on maintenance chemo with only Pemetrexed every 3 weeks. So, good luck with your treatment! I have been doing walking every day throughout my chemo.
My oncologist said walking is the best exercise which can be done by anyone and I have been doing it ever since my diagnosis in January, 2021. Earlier to my diagnosis, I had been doing yoga with Suryanamaskar. But I stopped it after I found that the back pain I had then was because of the bone lesions in my spine, shoulder and numerous other places in the skeleton. The bone lesions might have even caused fractures, had I continued with strength training!